The Carrying Behavior of Water-Based Fracturing Fluid in Shale Reservoir Fractures and Molecular Dynamics of Sand-Carrying Mechanism

• Published in: Processes Vol. 12; no. 9; p. 2051
• Main Authors: Li, Qiang, Li, Qingchao, Wang, Fuling, Wu, Jingjuan, Wang, Yanling
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.09.2024
• Subjects: Boron; Carrying capacity; Chemical synthesis; Chemicals; Clean technology; Collaboration; Crack propagation; Crosslinking; Crude oil; Drag coefficients; Economic development; Energy; Fluids; Fossil fuels; Fracture mechanics; Fracturing; Functional groups; Hydrochloric acid; Hydrogen; Low temperature; Low temperature resistance; Molecular dynamics; Oil fields; Oil recovery; Petroleum mining; Reservoirs; Rheological properties; Rheology; Sand; Sand transport; Shale; Silica; Solar energy; Stability; Temperature; Thickening; Titanium; Viscosity; Water; Working fluids; Zirconium; China
• ISSN: 2227-9717; 2227-9717
• DOI: 10.3390/pr12092051

Water-based fracturing fluid has recently garnered increasing attention as an alternative oilfield working fluid for propagating reservoir fractures and transporting sand. However, the low temperature resistance and stability of water-based fracturing fluid is a significant limitation, restricting the fracture propagation and gravel transport. To effectively ameliorate the temperature resistance and sand-carrying capacity, a modified cross-linker with properties adaptable to varying reservoir conditions and functional groups was synthesized and chemically characterized. Meanwhile, a multifunctional collaborative progressive evaluation device was developed to investigate the rheology and sand-carrying capacity of fracturing fluid. Utilizing molecular dynamics simulations, the thickening mechanism of the modified cross-linker and the sand-carrying mechanism of the fracturing fluid were elucidated. Results indicate that the designed cross-linker provided a high viscosity stability of 130 mPa·s and an excellent sand-carrying capacity of 15 cm2 at 0.3 wt% cross-linker content. Additionally, increasing reservoir pressure exhibited enhanced thickening and sand-carrying capacities. However, a significant inverse relationship was observed between reservoir temperature and sand-carrying capacity, attributed to changes in the drag coefficient and thickener adsorption. These results verified the effectiveness of the cross-linker in enhancing fluid viscosity and sand-carrying capacity as a modified cross-linker for water-based fracturing fluid.